1. Field of the Invention
This invention relates to a gate lock for a fence, and more particularly, to a self locking, relatively high security gate lock for chain link fences.
2. Prior Art
Chain link fences are well known. Typically such fences include a frame having numerous poles disposed at fixed intervals which support a mesh of thick metal wire which forms a screen. The screen is typically secured to the poles by pieces of wire. To provide a gate in an opening between two poles of the chain link fence, a gate about the size of the opening is hingedly mounted to the pole or fence post on one side of the opening. An oarlock or fork latch is typically hingeably attached to the opposite pole of the gate. When the gate is moved to the closed position, the oarlock or fork latch is moved from a vertical position to a horizontal position where it receives the pole of the fence in the U-shaped portion of the oarlock.
Typically, to lock the gate when the oarlock is in the closed position, i.e. horizontal, openings in the lock and collar are provided which line up, and a padlock is passed through the openings to lock them in their aligned position. With the lock in place, the oarlock cannot be moved from the horizontal closed position to the vertical open position. Thus the gate is locked.
The drawbacks of such a method of locking a chain link gate include the difficulty and complexity in opening and closing the lock and gate, the potential to lose or misplace the lock, and the inherent weakness of the lock to tampering by an intruder. The loss of the lock occurs frequently because the padlock has to be removed from the gate to complete the locking and unlocking operation. Further, in order to unlock the gate, two hands must be used. One hand to hold and steady the lock and another hand for inserting the key to open the lock.
Further, of recent date many state and/or local governmental laws and/or regulations now specify that a self latching gate latch device is required for swimming pool areas. The aforedescribed type devices are not self latching and, when left unlocked, as they are apt to be, can be easily opened by children and can pose a substantial risk, particularly when used for swimming pool areas or other potentially hazardous areas.
U.S. Pat. No. 4,691,541 to the inventor herein, McQuade (hereinafter "McQuade '541") eliminates the risk of losing or misplacing the lock because the locking device is always attached to the gate frame. At no time is the lock removed from the gate. To open the lock one must simply insert the key and turn. When the lock is turned the lock cylinder releases the lock bar from the oarlock which locks the gate. The oarlock is then moved from its locked horizontal position to the vertical unlocked position.
Improvements to the security of the gate of McQuade '541, by the same inventor include the inventions described and claimed in U.S. Pat. No. 4,919,463 (hereinafter McQuade '463) and in copending application 07/461,169, filed Jan. 5, 1990, now U.S. Pat. No. 5,024,473 (hereinafter McQuade '473).
McQuade '463 describes a gate latch for a chain link fence which has an oarlock latch that is pivotal from a vertical position to a horizontal position, the oarlock having means thereon to lock the oarlock to the collar. A means is also provided which is formed on the collar for interfitting with the locking means and for enclosing a portion of the oarlock to lock the oarlock to the collar and inhibit access to the enclosed portion of the oarlock.
McQuade '473 describes a similar gate locking device for a fence which includes a security box having a dead bolt means affixed to the security box whereby when the oarlock is moved to the horizontal locked position and the dead bolt is extended, the gate is securely locked to prevent unauthorized intrusion.
Other latch and lock devices are described in the following U.S. Pat. Nos.:
315,284 to Hewitt: PA0 303,225 to Jordan; PA0 1,168,234 to Tausch; PA0 1,179,852 to Louden; PA0 1,319,187 to Sumners: PA0 1,429,389 to Weintz: PA0 2,074,759 to Richards; PA0 2,194,408 to Sluss: PA0 2,510,520 to Remmele; PA0 2,666,660 to Younoworth; PA0 2,809,063 to Taylor: PA0 3,042,435 to Wiesler: PA0 3,083,561 to Sussing: PA0 3,270,536 to Sprung: PA0 3,307,384 to Sinervo PA0 3,355,207 to Newman: PA0 3,702,549 to Solovieff et al; PA0 3,774,947 to Duncan: PA0 3,926,018 to Joersz; PA0 3,934,436 to Candlin et al; PA0 4,387,916 to Lenino et al; PA0 4,592,578 to Martin; and PA0 French Pat. No. 584,589 to Hutin.
All of these aforecited patents are relatively complicated to lock and none of these references teach or suggest a self locking gate latch which, when the gate is swung closed, automatically locks to prevent the opening of the gate.